Citing Joel Feinerg's "offense principle," Palmer reports nudity is illegal because it not only has a "unique ability to demand our attention" but produces "an unpleasant mental state such as shame, disgust, or anxiety in observers."

Plus, Palmer points out, the allure of nudity can spread past just the single naked person and encourage prostitution, former Supreme Court Justice David Souter wrote in the 1991 decision in the case of Concur v. Glen Theatre, Inc.

So basically, according to Slate's explainer, nudity is illegal because it makes us uncomfortable and ashamed of ourselves when we can't look away.